public static void main(String[] args) {

Solution139 s = new Solution139();

System.out.println(s.wordBreak("leetcode", Arrays.asList("leet", "code")));

System.out.println(s.wordBreak("applepenapple", Arrays.asList("apple", "pen")));

}

public boolean wordBreak(String s, List<String> wordDict) {

HashSet<String> wordDictSet = new HashSet<>(wordDict);

boolean[] dp = new boolean[s.length()];

for (int i = 0; i < s.length(); i++) {

for (int j = 0; j <= i; j++) {

if ((j == 0 || dp[j-1]) && wordDictSet.contains(s.substring(j, i+1))) {

dp[i] = true;

break;

}

}

}

return dp[s.length() - 1];

}